1. Field of the Invention
The invention concerns an internal combustion engine with bearing shells (bearing seats, bushings), which are formed of thermal sprayed layers various bearing materials, as well as processes with production of bearing shells for internal combustion engines including the steps: mechanical conditioning of the bearing surface, coating the bearing surface with the material of the bearing shell using arc wire spraying, atmospheric plasma spraying, or high speed flame spraying, and then flattening finishing processing of the sprayed on layer. The invention concerns in particular bearing shells, which are provided on a connecting rod or piston rod.
2. Related Art of the Invention
Bearings in internal combustion engines are, as a rule, slide bearings. The bearing load typically exhibits force in a primary direction. Besides being able to accept force in this primary direction of force, there is also the problem of the embedding of dirt in the bearing material which provides a substantial demand on the slide bearing. Preferably, thus, with respect to the bearing load in the direction of force, a very sustainable bearing layer should be selected and the bearing layer should exhibit tolerance to dirt in the direction of the load. For this, typically a bifurcated bearing shell arrangement is selected, which is formed by two half-shells of different materials introducible into the bearing. These are introduced into the motor structure which is divided for bearing, and which are screwed together with an appropriate bearing play or clearance.
Recently the bearing layers have been applied directly upon the substrate material. Thus, for example, from DE 197 31 625 a connecting rod or piston rod is known, which has a bearing layer with a layer thickness between 150 to 800 μm. The bearing layer is applied by means of thermal spray processes, in particular by plasma spraying, and is comprised of a metal alloy, in certain cases in conjunction with dry lubricants.
From DE 10035032 a process for producing a connecting rod with a bearing layer is known, wherein the bearing layer is preferably applied by means of thermal spray processes, in particular plasma spraying or arc wire spraying, and preferably is comprised of Al/Cu-alloy or Cu/(Zn, Al, Sn)-alloy.
From DE 100 35 031 likewise sliding surfaces obtained by thermal spraying are known. Therein the sliding layers exhibit a gradual change in the composition of the coating with increasing coating layer. Preferably the layer is comprised of CuAl-alloy close to the substrate and, going away from the substrate, with an increasing proportion of titanium oxide.
The known processes lead to bearing layers with an even or gradual characteristic profile over the entire bearing surface.